1. Field of the Invention
The present invention relates generally to a method and apparatus for reducing logic activity in a microprocessor, and more particularly pertains to a method and apparatus for reducing logic activity in a microprocessor which leverages off the variations in effective bit-widths of operations in an application in controlling the total energy/power consumed during a workload execution. Energy or power consumed during a workload's execution in a microprocessor is partly due to the bit transitions or logic activity experienced in the course of processing. Hence, the larger the number of bits that have to transition during any one operation, the higher the activity levels and the likelihood of more energy being consumed.
2. Discussion of the Prior Art
The datapath for today's microprocessors is getting larger, particularly to cover very large memory address space. Currently, the 32-bit datapath is commonplace, and 64-bits is becoming more widespread. However, a closer look at the effective operation width in typical applications reveals that as much as 70% of instructions in some applications can be executed with an 8-bit wide functional unit. This means that the typical microprocessor today is unnecessarily executing longer operations, causing unnecessary bit transitions, and ultimately consuming more energy than is really necessary for accurate program execution.